1. Field of the Invention
This invention relates to a process for producing an oleaginous composition. More particularly, it relates to a process for producing an oleaginous composition which has a high nutritive value, shows excellent melting behaviors and is highly available as a confectionery fat such as a hard butter.
2. Description of the Prior Art
Conventional hard butters mainly comprise symmetric triglycerides including oleodipalmitin (POP), oleopalmitostearin (SOP) and oledistearin (SOS), each having an oleate group at the 2-position, similar to cacao fat.
In order to further elevate the nutritive value of a confectionery fat such as a hard butter, it is necessary to introduce more nutritious polybasic unsaturated fatty acids such as linolic, linolenic, arachidonic, eicosapentaenoic and docosahexaenoic acids thereto.
It is expected that these polybasic unsaturated fatty acids, which are essential fatty acids and serve each as a precursor of a hormone-like substance such as prostaglandin, leukotriene and thromboxane, may exert some pharmacological effects, for example, improving arteriosclerosis and lowering the blood cholesterol level.
In order to introduce highly nutritious linoleic acid into a hard butter, a liquid oil containing a large amount of linolic acid may be blended with the hard butter. However it was reported that a hard butter comprising a liquid oil containing a large amount of linoleic acid, i.e., corn oil would exhibit an insufficient hardness and that the presence of a symmetric triglyceride (SLS) having an linolate group at the 2-position in a symmetric triglyceride would deteriorate the physical properties of the hard butter even at a content as low as 5% (cf. Japanese Patent Publication No. 28530/1982).
Further it was reported that when the content of linoleic acid in an oily material exceeded 14%, the resulting confectionery fat showed undersirable physical properties (cf. Japanese Patent Laid-Open No. 155048/1987).
Thus it has been believed hitherto that the presence of polybasic unsaturated fatty acids such as linoleic acid in a confectionery fat is undesirable.